Note: Descriptions are shown in the official language in which they were submitted.
CA 02989732 2017-12-15
DRIVE ARRANGEMENT FOR A RAIL VEHICLE, RAIL VEHICLE WITH A DRIVE
ARRANGEMENT AND METHOD FOR PRODUCING THE DRIVE ARRANGEMENT AND
THE RAIL VEHICLE
The invention relates to a drive arrangement for a rail vehicle and a rail
vehicle with a drive
arrangement. The rail vehicle particularly is a light rail vehicle, such as a
streetcar. The
invention further relates to a method for producing the drive arrangement and
the rail vehicle.
The invention particularly relates to low-floor rail vehicles, particularly
light low-floor rail
vehicles. The floors of the passenger compartments of such rail vehicles are
at a height level not
above, or even below, the height level of the axes of rotation of the wheel
discs of the wheels of
the rail vehicle, particularly in the outer door area between the bogies. This
leaves little space for
the traction motors of the rail vehicle.
As EP 1 197 412 A2 describes, for example, an external longitudinal drive can
be provided, i.e.
the longitudinal axis of the rotor and the traction motor extends in the
direction of travel or
substantially in the direction of travel, and the traction motor is disposed
outside the space
between the wheel discs of a wheelset. In other words, the drive shaft extends
outside
approximately parallel to the longitudinal members of the bogie, which extend
in the
longitudinal direction of the vehicle, that is, approximately in the direction
of travel, particularly
between two wheelsets of the bogie. Such longitudinal drives typically
comprise a bevel gear.
Disadvantages include the complexity of the transmission and the noises with a
high sound level
that develop, particularly at higher rotational speeds. The traction motor is
therefore configured
for relatively low maximum rotational speeds. This again results in a
relatively great weight and
large installation space.
Further conceivable are traction motors whose rotor and drive shaft extend in
the vertical
direction and which can be disposed in the transition areas between various
vehicle bodies of
the rail vehicle. The disadvantage of this design is the complexity of the
transmission via which
the drive power from the traction motor is introduced to the wheelset shaft.
Furthermore, the traction motor can be disposed above a wheel disc of a
wheelset, e.g.
underneath the seat faces of vehicle seats. However, the overall height of the
transmission
requires a separate oil pump with the respective risk of failure.
1
CA 02989732 2017-12-15
The moving masses and the inert masses of the drives are relatively large for
the drives of low-
floor rail vehicles mentioned above. Since at least parts of the drive, such
as the transmission,
but depending on the design also the traction motor, are fastened to,
suspended at, or supported
on the bogie, the bogie itself must be of an accordingly stable and therefore
typically heavy and
bulky design.
In addition to the concepts for disposing the traction motor mentioned above,
it is also known
from prior art to provide a transverse motor in which the longitudinal axis of
the rotor and thus
of the drive shaft of the motor extend approximately parallel to the
longitudinal axis of the
wheelset shaft. For example, WO 2011/141510 Al discloses several variants of
fastening or
coupling such a transverse drive to a bogie.
It is an object of this invention to provide a drive arrangement and a rail
vehicle with such a
drive arrangement which enlarge the space for other design elements and other
devices of the
rail vehicle and particularly facilitate the use of a traction motor with a
low overall volume
and weight. It is another object of the invention to provide a method for
producing a drive
arrangement and a rail vehicle with which these objectives can be achieved.
According to a basic idea of the present invention, it is proposed to
integrate a traction motor of
the rail vehicle drive into a load-bearing structure of a bogie. At least a
portion of the load-
bearing structure of the bogie thus performs two functions: on the one hand,
it receives at least a
portion of the weight of the rail vehicle and transfers it via at least one
wheelset onto the
running rails, and on the other hand it contains at least one partial volume
of the traction motor.
The concept of containing the partial volume or the volume refers to the
volume of the load-
bearing structure of the bogie, which is defined by the envelope surfaces of
the volume. At least
one partial volume of the traction motor is located inside these envelope
surfaces. The load-
bearing structure of the bogie particularly comprises a recess or hollow space
which is thus
located inside the envelope surfaces and in which at least a portion of the
traction motor is
incorporated.
This reduces the installation volume needed for the traction motor outside the
load-bearing parts
of the bogie. Furthermore, at least the section of the drive motor integrated
into the bogie is
protected from external influences, such as shocks. For example, a housing of
the traction motor
can be designed in a more space-saving manner (e.g. with a lower housing wall
thickness), or at
2
CA 02989732 2017-12-15
least a portion of the housing can be omitted. In other words, the load-
bearing structure of the
bogie can form at least a portion of the motor housing.
It is further proposed to design the drive arrangement with a transverse
drive, which means
that the longitudinal axis of the traction motor in the direction of which the
mechanical drive
power is transmitted from the motor to the wheel or wheelset extends
transversely to the
direction of travel of the rail vehicle, particularly parallel to a wheelset
shaft or a virtual axle
which connects the center points of the wheels of a wheelset. The longitudinal
axis of the rotor
of the traction motor therefore particularly extends in the horizontal
direction, e.g. when the
rail vehicle is moving along a rail not inclined to the left or right during
travel. This is typically
the case when the vehicle is traveling straight ahead.
The transverse drive allows the use of a transmission that can do without
bevel gears for
transmitting the drive power from the motor drive shaft to the wheel or
wheelset. Particularly,
the drive arrangement can comprise a spur-gear transmission, wherein the
traction motor
transmits the drive power during operation via an input (drive) shaft of the
spur-gear
transmission into the same. Particularly, the input shaft and an output
(drive) shaft of the spur-
gear transmission can extend parallel to the wheelset shaft or the virtual
wheelset axle mentioned
above. It is also conceivable that the wheelset shaft is the output shaft of
the spur-gear
transmission or that the wheelset shaft and the input shaft extend coaxially.
Compared to a bevel gear transmission, a spur-gear transmission has the
advantage that it is
smaller in overall volume, has a lighter weight when using similar materials,
and produces less
noise at the same rotational speeds. A spur-gear transmission also has the
advantage that it is
simple to implement a multi-stage transmission, which in turn allows large
transmission ratios of
the speeds of input shaft and output shaft of the transmission with little
noise generation. Multi-
stage spur-gear transmissions, but also single-stage spur-gear transmissions,
are therefore
suitable for building drives with a light weight and a large transmission
ratio. This again makes it
possible to operate the traction motor at higher speeds and therefore design
it smaller to achieve
the same driving power. This in turn makes it easier to integrate the traction
motor into the load-
bearing structure of the bogie, that is, a larger portion or even the entire
traction motor can be
located inside the envelope surface of the bogie.
One advantage of saving space, both by the at least partial integration of the
traction motor into
the load-bearing structure of the bogie and by using a spur-gear transmission
is that the outward
3
CA 02989732 2017-12-15
lateral projection of components of the drive arrangeÃd compared to other
drive arrangements
with external parts. This advantage is particularly pronounced with respect to
known
arrangements in which the drive motor is completely outside the longitudinal
members of the
load-bearing structure of the bogie. This reduces the width of the clearance
profile of the vehicle
at the level of the bogie, particularly when cornering. This free space is
also beneficial for
providing sufficient free space into which parts of the rail vehicle that are
spring-mounted to the
bogie can move. In addition, the at least partial integration into the bogie
also provides free space
for the design of a low-floor rail vehicle. This particularly applies to
transitions between different
vehicle bodies of the rail vehicle, which are typically disposed near the
bogies.
Particularly in bogie designs with longitudinal members extending in the
direction of travel of
the rail vehicle on opposite sides right and left in the direction of travel,
the traction motor can
be fully or partially integrated into a recess and/or hollow space of a
longitudinal member. This
has the advantage that the spur-gear transmission can be disposed on the
longitudinal member in
the immediate vicinity of the traction motor. The input shaft of the spur-gear
transmission can
therefore be particularly short, which saves weight and costs.
The longitudinal member can particularly comprise a recess that extends from
the outer side of
the bogie into the longitudinal member and, for example, comprises a closed
circumferential
edge. It is preferred that the shape and size of the circumferential edge is
adjusted to the shape
and size of the outer circumference of the traction motor such that the stator
of the traction
motor is at least partially accommodated in the recess and is in contact with
the edge of the
recess on different sides of the outer circumference. The edge of the recess
thus holds the
stator and the traction motor in the holding position.
The recess can extend into the interior of the longitudinal member, but not
all the way through
it. This provides a stop for inserting the traction motor into the recess,
which can be formed, for
example, by the rear wall of the recess. It is preferred, however, that said
recess extends all the
way through the longitudinal member. This increases the space for
accommodating the traction
motor, and a portion of the traction motor can also be located on the inner
side of the
longitudinal member.
Alternatively or in addition, at least one partial volume of the traction
motor can be integrated
into a transverse member of the bogie. The transverse member extends in the
horizontal
direction (when the rail vehicle travels straight ahead). Using a transverse
member has the
4
CA 02989732 2017-12-15
advantage that there is sufficient space available in the direction of the
longest length of the
transverse member for installing the traction motor, particularly the overall
length of the
traction motor.
Alternatively or in addition to the volume or partial volume of the traction
motor, a part of a
cooling device for cooling the traction motor during its operation can be
integrated into the load-
bearing structure of the bogie. Particularly, a fan of the cooling device for
cooling an air flow can
at least partially be integrated into the load-bearing structure of the bogie.
Alternatively or in
addition, a section of the cooling fluid line of the cooling device for
conducting a cooling fluid
flow can be integrated into the load-bearing structure of the bogie.
Furthermore alternatively or
in addition, a cooling fluid pump of the cooling device for driving a cooling
fluid flow can at
least partially be integrated into the load-bearing structure of the bogie.
Furthermore alternatively
or in addition, a heat transfer unit for transferring the heat of a cooling
fluid to the load-bearing
structure and/or the environment of the load-bearing structure can at least
partially be integrated
into the load-bearing structure of the bogie.
Particularly, cooling fluid lines can run inside the load-bearing structure,
e.g. from the
traction motor via lines inside the longitudinal member and/or transverse
member of the
load-bearing structure, optionally via a cooling fluid pump that is integrated
into the load-
bearing structure and optionally via an additional heat exchanger for re-
cooling the cooling
fluid on its way back to the traction motor.
In all these cases, the at least partial integration of the cooling device
results in a free space that
is available for other design elements and other devices of the rail vehicle.
If both at least one partial volume of the traction motor and at least one
partial volume of the
cooling device for cooling the traction motor during its operation are
integrated into the load-
bearing structure of the bogie, components of the cooling device can be
eliminated. Particularly,
integration of at least a portion of the cooling device allows dissipation of
the heat that is
generated during the operation of the traction motor via the load-bearing
structure of the bogie.
The load-bearing structure can therefore particularly be used as a heat
transfer unit for
transferring the heat of a motor cooling fluid to the ambient air.
Particularly, a portion of the cooling device, e.g. the additional heat
transfer unit, the cooling
fluid pump and/or the fan, can be inserted into a recess of a longitudinal
member of the load-
CA 02989732 2017-12-15
bearing structure of the bogie. The same that has been said above about the
recess for inserting
the traction motor particularly applies to this recess. Particularly, both a
recess for the traction
motor and at least one recess for the part of the cooling device can be
provided. Particularly, the
traction motor and/or at least a portion of the cooling device can be inserted
into a longitudinal
member of the load-bearing structure.
Particularly, the following is proposed: A drive arrangement for a rail
vehicle, comprising:
= a load-bearing structure of a bogie,
= a traction motor with a stator and a rotor, and
= a transmission for transmitting drive power of the traction motor to at
least one
wheelset of the bogie,
wherein the drive arrangement is designed as a transverse drive, at least one
partial volume of
the traction motor is integrated into the load-bearing structure, the
transmission is a spur-gear
transmission, wherein an input shaft of the spur-gear transmission is coupled
to the rotor of the
traction motor and an output shaft of the spur-gear transmission can be or is
coupled to at least
one wheel of the wheelset.
Particularly, one of the embodiments of the drive arrangement that are
described in this
specification can be a component of a rail vehicle.
Furthermore, the following is proposed: A method for producing a drive
arrangement for a rail
vehicle, particularly an embodiment of the drive arrangement, which are
described in this
specification, wherein:
= a transmission for transmitting drive power to a wheel or a wheelset of a
bogie directly
and/or via a traction motor is supported on a load-bearing structure of the
bogie, and
= a rotor of the traction motor is coupled to an input shaft of the
transmission,
wherein the drive arrangement is designed as a transverse drive, at least one
partial volume
of the traction motor is integrated into the load-bearing structure, and a
spur-gear
transmission is used as the transmission.
Particularly, when producing a rail vehicle, one of the embodiments of a drive
arrangement that
are described in this specification can be produced.
Particularly, an axis of rotation of the rotor about which the rotor rotates
when the traction
motor is in operation and the input shaft of the spur-gear transmission can
extend in the
6
CA 02989732 2017-12-15
horizontal direction. This refers to the case that the rail vehicle travels
straight ahead during an
operation of the drive arrangement in the rail vehicle. Particularly, it is
therefore also
conceivable to have the axis of rotation of an output shaft of the spur-gear
transmission also
extend in the horizontal direction. The drive power transmission from the
traction motor to a
wheel or wheelset shaft thus exclusively takes place by rotational movements
about horizontally
extending axes of rotation. It is therefore not necessary to change the
direction of the rotational
movements (as for example in bevel gear transmissions).
As mentioned above, the load-bearing structure of the bogie can comprise a
longitudinal member
that extends in a direction of travel during the operation of the rail
vehicle, wherein the volume
or partial volume of the traction motor is integrated into the longitudinal
member. In this case, a
favorable, at least partially balanced weight distribution can be achieved,
particularly in the
following manner: The load-bearing structure of the bogie comprises aright-
hand area that is on
a right side in the direction of travel when the rail vehicle is in operation,
and a left-hand area
that is on a left side in the direction of travel when the rail vehicle is in
operation. The drive
arrangement comprises a first and a second traction motor, wherein at least
one partial volume of
the first traction motor is integrated in the right-hand area and at least one
partial volume of the
second traction motor is integrated in the left-hand area. Particularly, the
first traction motor and
the second traction motor can each be coupled to at least one wheel of the
bogie via a spur-gear
transmission. Particularly, the overall arrangement of the two traction motors
and the two spur-
gear transmissions can, when viewed from above, be point-symmetrical with
respect to a center
of the central longitudinal axis of the rail vehicle. This longitudinal axis
extends in the direction
of travel of the rail vehicle. In other words, the arrangement of the first
traction motor with the
first spur-gear transmission coupled to it is point-symmetrical to the
arrangement of the second
traction motor with the second spur-gear transmission coupled to it.
Exemplary embodiments of the invention will now be described with reference to
the
enclosed drawing. Wherein:
Fig. 1 shows a top view of a bogie with two drive arrangements,
Fig. 2 shows a side view of the bogie shown in Fig. 1, and
Fig. 3 shows a front view of the bogie shown in Fig. 1 and Fig. 2 from the
right-hand
side in Fig. 1 and from the right-hand side in Fig. 2.
7
CA 02989732 2017-12-15
The bogie 1 shown in Fig. 1 comprises two wheelsets 2a, 2b and 2c, 2d, wherein
the wheels 2a
and 2b or 2c and 2d, respectively, are each non-rotatably connected via a
wheelset shaft 3a, 3b,
i.e. the wheels rotate synchronously about the axis of rotation, except for
elasticity-related
torsions about the axis of rotation of the wheelset shaft.
The wheelset shafts 3a, 3b are coupled to the load-bearing structure of the
bogie 1 via two pivot
bearings not shown in detail. In the exemplary embodiment shown, the load-
bearing structure
comprises two longitudinal members 5a, 5b and a transverse member 4. The
longitudinal axis of
the longitudinal members 5a, 5b, which runs from left to right in Fig. 1,
extends in the direction
of travel of the rail vehicle. The transverse member 4 connects the
longitudinal members 5a, 5b
at their central sections. This results in a H-shaped load-bearing structure
of the bogie 1. But the
invention is not limited to such a load-bearing structure of a bogie. Other,
already known bogie
designs can be used for integrating the traction motor and/or the cooling
device. In the
exemplary embodiment of Fig. 1, the pivot bearings for supporting the wheelset
shafts 3a, 3b are
located in the opposite longitudinal end sections of the longitudinal members
5a, 5b.
A traction motor 7a, 7b is partially integrated in the longitudinal members
5a, 5b. Furthermore,
a cooling device 9a, 9b for cooling one of the traction motors 7a, 7b is
partially integrated in
each of the longitudinal members 5a, 5b. Each of the longitudinal members 5a,
5b in the
exemplary embodiment has a recess in each of t he two longitudinal sections
that extend
towards the transverse member 4 in the direction of the pivot bearings, which
recesses extend
from the outer side (top and bottom in Fig. 1) into the interior of the
longitudinal members 5a,
5b. The recess for the second traction motor 7b is identified by the reference
symbol 6b in Fig.
2. The recess for the second cooling device 9b is identified by the reference
symbol 8b in Fig.
2. At least the recesses 8 for the cooling devices 9a, 9b extend through the
longitudinal
members 5a, 5b all the way to their inner side. Thus, they form a housing that
is open on two
sides for receiving the cooling device 9. Optionally, this is also the case
with the recesses 6 for
the traction motors 7. This makes assembly of the cooling device 9 or the
traction motor 7,
respectively, easier. In the exemplary embodiment, the traction motor 7 or
cooling device 9,
respectively, project outwards from the recess.
The view of the first longitudinal member 5a from outside, i.e. from the top
in Fig. 1, is similar
to the view of the second longitudinal member 5b, which is shown in Fig. 2.
Therefore, the
overall arrangement of the motors 7a, 7b (as well as of the transmissions,
which will be
discussed in detail below) is point-symmetrical to the center P of the
transverse member (Fig. 1).
8
CA 02989732 2017-12-15
The weight distribution is balanced in this manner. The masses on the right
and left vehicle sides
are about equal.
Each of the traction motors 7a, 7b comprises a drive shaft which is part of
the rotor. The rotor
12b of the second traction motor 7b is represented schematically by broken
lines in Fig. 1. It is
coupled to the input shaft 13b (also schematically represented by broken
lines) of the associated
spur-gear transmission 11b, which is located on the outer side of the
longitudinal member 5b.
The second spur-gear transmission llb comprises an output shaft 14b (as shown
schematically
on the bottom right of Fig. 1, also by broken lines), which is coupled to the
second wheelset shaft
3b. Therefore, drive power is transmitted via the second spur-gear
transmission llb to the
second wheelset shaft 3b when the second traction motor 7b is in operation,
and the wheelset is
thus driven by the wheels 2c and 2d. This applies analogously to the coupling
of the first traction
motor 7a to the associated spur-gear transmission lla on the outer side of the
first longitudinal
member 5a.
In the front view of Fig. 3, the spur-gear transmissions ha and lib can be
seen on the outer
sides on the right and left in Fig. 3 because they project further than the
traction motors. The
second transmission 11b and the schematically represented input shaft 13b and
output shaft 14b
can be seen in the side view of Fig. 2.
The cooling device 9a, 9b, which is partially integrated into the longitudinal
member 5a, 5b, is a
heat exchanger for re-cooling the cooling fluid in the exemplary embodiment
shown. A cooling
fluid pump that circulates the cooling fluid in a cooling circuit not shown in
detail can also be
integrated into the bogie. Cooling fluid lines therefore extend, for example,
from each of the
traction motors 7a, 7b inside the longitudinal member 5a, 5b via the cooling
fluid pump and heat
exchanger back to the respective traction motor 7a, 7b. The cooling fluid
circuits in the different
longitudinal members 5a, 5b are separate from one another in the exemplary
embodiment shown.
Even without an additional heat exchanger, heat is transferred from the
cooling fluid that is
heated by the traction motor 7a, 7b to the material of the longitudinal member
5a, 5b since the
cooling fluid lines are integrated into the respective longitudinal members
5a, 5b. The
= longitudinal member 5a, 5b acts as a heat transfer unit to the ambient
air. When the rail vehicle is
traveling, air flows mostly turbulently over the surfaces of the longitudinal
member 5a, 5b,
effectively air-cooling said member. Optionally, a fan can be provided, which
causes an
additional air flow along surfaces of the longitudinal member and along the
surface of the partial
9
CA 02989732 2017-12-15
volume of the traction motor 7a, 7b that projects from the longitudinal member
5a, 5b,
particularly at low speeds of the rail vehicle.
